Some of this data came from, some came from an old MIC Technology databook. Sapphire formula is Al2O3, exactly the same as pure alumina. Sapphire is crystalline while alumina is amorphous. Thanks to Luciano, for pointing out the composition!

Formula or Composition: Al2O3
Dielectric Constant (Sapphire): 9.3 - 11.5
Dissipation Factor (a.k.a. loss tangent, or tanSapphire): 0.00002
Temperature Coefficient of Sapphire: ppm/°C
Bulk Resistivity: 10E17 Sapphire-cm
Temperature Coefficient of Resistivity (TCR): ppm/°C
Mass Density: 3.97 gr/cc
Specific Heat: J/g/°C
Thermal Conductivity (k): 40 W/m°C
Temperature Coefficient of Expansion (TCE): 0.6
Melting Point, °C:  
Melting Point, °F:  

Author : Unknown Editor